FSAD refers to inhibition of the "vasocongestion–lubrication response" to sexual stimulation. In the most recent edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR), FSAD is defined as the pervasive or recurrent inability to attain, or to maintain until completion of the sexual activity, an adequate lubrication–swelling response of sexual excitement, coupled with marked distress or interpersonal difficulty. The DSM classification of sexual disorders has been derived from phases of the sexual response cycle, on the basis of the work of Masters and Johnson and Kaplan. This model depicts a sexual desire phase and a subsequent sexual arousal phase, characterized by genital vasocongestion, followed by a plateau phase of higher arousal, resulting in orgasm and subsequent resolution. It is assumed in this model that women’s sexual response is similar to men’s, such that women’s sexual dysfunction in DSM-IV mirrors categories of men’s sexual dysfunction. In contrast to the third edition of the DSM manual, subjective sexual experience is no longer part of the definition, possibly in a further attempt to match norms and criteria for men’s and women’s sexual dysfunctions.

There are a number of serious problems with the current DSM-IV classification criteria. Firstly, although the DSM-IV explicitly requires the clinician to assess the adequacy of sexual stimulation only when considering the diagnosis of FOD, adequacy of sexual stimulation is a critical variable in evaluating each of the female sexual dysfunctions, and FSAD in particular. Exactly what is adequate sexual stimulation? Some sort of physical (genital) stimulation is a necessary, but not necessarily sufficient, prerequisite for arousal. For many women, adequate sexual arousal involves physical as well as "psychological" and "situational" stimulation, such as intimacy with a partner, the exchange of confidences, the sharing of hopes and dreams and fears, and not only directly prior to the sexual event. What if certain types of sexual stimulation have been adequate in the past, but not anymore? Is it evidence of FSAD, or could it be explained in terms of habituation or an adaptation to changing life circumstances? And what is meant by "completion of the sexual activity?" Is it masturbation to orgasm, sexual contact with a partner, sexual contact including coitus? These are very different activities that are known to differ in their sexually arousing qualities.

Secondly, the description of the first problem demonstrates that clinical judgements are required about sexual stimulation and the severity of the problem, the validity of which is questionable. The clinician has to evaluate what is normal, based on age, life circumstances, and sexual experience. Research on the basis of which clear criteria can be formulated, is lacking. There is a great variety in the ease with which women can become sexually aroused and which types of stimulation are required.

Thirdly, due to the lack of clear diagnostic criteria, it is often unclear in which cases an FSAD diagnosis or one of the other three main DSM-IV diagnoses is appropriate. The four primary DSM-IV diagnoses pertaining to lack of desire, arousal, orgasm problems or sexual pain, are not independent. Only very infrequently do women present with sexual arousal problems when seeking help for their sexual difficulties, but that does not mean that insufficient sexual arousal is an unimportant factor in the etiology of these difficulties. In actual clinical practice, classification is often done on the basis of the way in which complaints are presented. If the woman is complaining of lack of sexual desire, the diagnosis of hypoactive sexual desire disorder is easily given. If she reports trouble reaching orgasm or cannot climax at all, FOD is the most likely diagnosis. If she reports pain during intercourse, or if penetration is difficult or impossible, the clinician may conclude that dyspareunia or vaginismus is the most accurate diagnostic label. In general, women have difficulty perceiving genital changes associated with sexual arousal. However, women who report little or no desire for sexual activity, lack of orgasm, or sexual pain, may in fact be insufficiently sexually aroused during sexual activity. It is particularly difficult to differentiate between FSAD and FOD. FOD is defined as the persistent or recurrent delay in, or absence of, orgasm following a normal sexual excitement phase. In cases where the clinician does not have access to a psychophysiological test in which a woman is presented with (visual and/or tactile) sexual stimuli, while genital responses are being measured, it cannot be established that her deficient orgasmic response occurs despite a normal sexual excitement phase, unless she reports feelings of sexual arousal. Ironically, this subjective criterion has been removed in the DSM-IV.

Studies investigating the efficacy of psychological treatments for sexual dysfunction have demonstrated that directed masturbation training combined with sensate focus techniques is very effective for women with primary anorgasmia to become orgasmic. In fact, this is the only psychological treatment of sexual dysfunctions that deserves the label "well established," and is probably efficacious in secondary orgasmic disorder. The success of this treatment suggests that lack of adequate sexual stimulation is an important etiological factor underlying primary, and probably also secundary, anorgasmia. Consequently, if the clinician would strictly adhere to the DSM-IV criteria, the diagnosis of neither FSAD nor FOD would be appropriate, because the problem can be reversed by adequate sexual stimulation. In any case, primary orgasmic problems may not justify a separate diagnostic category. Perhaps the diagnosis of FOD should be restricted to those women who are strongly sexually aroused but have difficulty surrendering to orgasm. There are no clinical or epidemiological studies that differentiate between women with primary or secondary anorgasmia and other orgasm problems, so we do not know how prevalent this is. Segraves argued that FSAD hardly exists as a distinct entity, whereas we, in contrast, argue that in a classification system based on the etiology of sexual complaints, FSAD should be considered to be the most important female sexual dysfunction, with complaints of lack of desire and orgasm, and pain, frequently being consequences of FSAD.

Finally, there is a good deal of evidence that, especially for women, physiological response does not coincide with subjective experience. Women’s subjective experience of sexual arousal appears to be based more on their appraisal of the situation than on their bodily responses. We will address this issue extensively later in this chapter. Thus, in the DSM-IV definition of FSAD, probably the most important aspect of women’s experience of sexual arousal is neglected, given that absent or impaired genital responsiveness to sexual stimuli is the sole diagnostic criterion for an FSAD diagnosis.